A novel fastening system for connecting actuators or similar attachable devices to rotary valves, providing not only a means for securely clamping the valve and device together, and resisting reaction loads, but also ensuring an accurate index between the units.
The commonly used technique of clamping a bracket to a valve, then bolting the valve/bracket combination to an actuator often falls short of providing the required accurate indexing, particularly in cases where tightness of fit between the clamp and valve serves to locate the valve during final assembly with the actuator. Valves designed with integral mounting pads that permit direct actuator to valve bolting usually suffer this shortcoming as well, since, to fix the actuator position, they customarily depend on the fit between the attachment screws and clearance holes through which the attachment screws extend.
When greater indexing accuracy is demanded, dowel pins permanently fixed either to the valve or actuator that engage closely fitting holes in the other member, have been used successfully in conjunction with the attachment screws. Valve brackets that are machined to suit mating and locating features integral with the valve bodies have also proven successful.
Dowel pins provide good alignment accuracy, but suffer the disadvantages of machining time and expense required for their proper use, and dowel pins may not provide proper contact mating in the event the actuator or device requires replacement. The alternate use of machined valve brackets to provide for mating and alignment also suffers the disadvantages of added time and expense to manufacture and install the brackets.
It is an object of the invention to provide an improved mechanical method of quickly and accurately indexing an attachment for a valve to provide proper operating alignment of the attachment to the valve.
It is a further object of the invention to provide a positive means of engaging the contact surfaces between a valve and the attached device.
It is a further object of the invention to provide a mounting method which improves alignment and mating tolerances between valves and their attachments, without additional machining or intermediate parts.
The inventive method attaches valves to actuators, or similar devices, and satisfies the requirements of both soundness and accuracy, without recourse to dowel pins or other special fixtures. The subject method relies on two pins that are fast with the valve body, each pin being undercut near its exposed end, an actuator (or other device) with closely fitting mating holes that accept the pins, and means to secure the pins within the holes using cone-point or similarly shaped set screws that perpendicularly intersect the pins.
According to the invention there is provided a valve to attachment mounting system for joining an attachment to a valve having a valve body comprising: at least two flanged pins fast with one of the valve body and the attachment; at least two mating holes in the other of the valve body and the attachment for receiving the pins to locate the attachment relative to the valve body; a tapped hole extending transverse of each said mating hole; a screw engaging each said tapped hole; wherein said screws engagedly connect a flange of said flanged pins, axially tensioning said pins to draw said valve body into desired physical contact with said attachment.
Also according to the invention there is provided a rotary valve and an attachment connected by a mounting system comprising: at least two pins having a desired diameter and an axial centerline, said at least two pins each threadedly engaging a threaded bore in a valve body of the rotary valve; at least two holes in the attachment, each said hole having an axial centerline, each hole""s axial centerline being coaxially aligned with a said pin""s axial centerline; at least two tapped holes in the attachment, each with an axial centerline, each said tapped hole""s axial centerline being perpendicular to and offset from an associated said mating hole""s axial centerline; at least two screws, each set screw threadedly engaging one of said tapped holes; wherein said valve body is mated to said rotary valve attachment such that said at least two pins slidably mate with said at least two mating holes; and each said screw engagedly connects with an annular flange of a said pin to axially tension said at least two pins to draw said valve body to physical contact with said attachment.
Also according to the invention there is provided a method for connecting attachments to rotary valves comprising the steps of: fastening at least two flanged pins each to a bore in one of a valve body of the rotary valve and the attachment; machining at least two mating holes in the other of the valve body and the attachment, said mating holes being alignable with said pins; machining a tapped hole transversely of each of said mating hole; joining said valve body to said rotary valve attachment such that said pins mate slidably with corresponding said mating holes; and screwing a screw into each of said tapped holes; whereby said screws engagedly connect with each of said at least two flanged pins axially to tension said at least two pins to draw said valve body to physical contact with said rotary valve attachment.
Also according to the invention, there is also provided a valve to attachment mounting system for joining an attachment to a valve having a valve body comprising: at least two flanged pins fast with the valve body; at least two mating bores in the attachment for receiving the pins to locate the valve body relative to the attachment; a tapped hole in said attachment extending transverse of each said mating bore; a screw engaging each said tapped hole; wherein said screws engagedly connect with said flanged pins, axially tensioning said pin to draw said attachment into desired physical contact with said valve body.